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1 14th August 00:22
st
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Posts: 1
Default Why can I ping in one direction but not the other


I can connect to my desktop with one of my laptops, but not the other way
around. I am going through a Linksys router (used with VOIP) to a Netgear
router which is my DHCP. I can ping the desktop (192.168.0.6) with the
Laptop and can see the shared folders and copy to and from the desktop. I
CANNOT ping or connect from the desktop to the laptop (192.168.15.100). I use
the free ZoneAlarm and the laptop is in the trusted zone along with the
Linksys router. I can disable ZoneAlarm and get the same results.

Anybody got a clue?? What am I missing?

Thanks for the help.
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2 14th August 00:22
ron lowe
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Posts: 1
Default Why can I ping in one direction but not the other


Are they both getting addresses from the router?

What range of addresses is the router set up to issue?
What subnet mask is it issuing?

Assuming the subnet masks in use are 255.255.255.0,
then the machines are not in the same subnet.

One address is in the 192.168.0.x range, whilst the other is in
the192.168.15.x range.
That's unusual.

I'd expect the first 3 octets to be the same in this kind of setup.
eg: all 192.168.0.x

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Ron
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3 14th August 02:02
ron lowe
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Default Why can I ping in one direction but not the other


Considering further, the subnets ( odd as they are ) can't be the issue.
If they can ping in one direction, then there's a route there, and a route
back.

In that case, it's probably a firewall issue on the laptop.

Is the desktop in the trusted zone on the laptop?

Perhaps time to un-install firewalls untill you get it figured out.
Use the instructions on ZoneLabs site to un-install, don't just do it from
add/remove programs.

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Ron
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4 14th August 02:02
st
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Posts: 1
Default Why can I ping in one direction but not the other


Hey Chuck. The above link would not work.

The desktop is connected to the Netgear. The Linksys is connected to the
Netgear. the laptop is connected to the Linksys. The subnet is
255.255.255.0 on both machines.
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5 14th August 02:02
st
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Posts: 1
Default Why can I ping in one direction but not the other


The desktop is in the trusted zone on the laptop and the laptop can access
the desktop fine with the ZoneAlarm firewall on.

The laptop is in the trusted zone on the desktop as well.


I disabled the ZoneAlarms on both machines to see if it made a difference
and it didn't.

Steve
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6 14th August 02:02
ron lowe
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Default Why can I ping in one direction but not the other


AHH!

You have a double NAT configuration.

DSL
|
Netgear NAT Router -- Desktop
|
Linksys NAT Router
| |
Laptop VoIP phones

That's not going to work!
The laptop can ping the desktop, because it's an outbound connection through
the linksys NAT.
The desktop can't connect to the laptop because the NAT drops the
unsolicited inbound connection.

You need to connect the laptop to the netgear directly.
I know you said it's out of ports, but by directly I mean not via a router.
You can keep the linksys if you need it for VoIP.
Just don't use it for your LAN!
An additional switch is required.

DSL
|
Netgear NAT Router -- New Switch
| | |
Linksys NAT Laptop Desktop
Router
|
VoIP phones

Now, the laptop and desktop will both get 192.168.0.x addresses from the
Netgear.

--
Ron
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7 14th August 02:03
gerald vogt
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Posts: 1
Default Why can I ping in one direction but not the other


Well, it depends. I don't see the reason, why you would run NAT on the
Linksys anyway. Don't run the Linksys as gateway but as router and setup
routes on both routers. Then you are able to have traffic in both
directions.

Else, if you have two spare ports on the Linksys, it may be enough to
plug in the uplink (the on in the Linksys WAN port) into one of the LAN
ports.

Everything kind of depends though on which hardware you use...

Gerald
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8 14th August 02:03
harry putnam
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Posts: 1
Default Why can I ping in one direction but not the other


"ST" <ST@discussions.microsoft.com> writes:

Nobody seems to have pointedout that the above is a netmask not a
subnet. Clearing that up may bring more clarity.
The subnets presented so far are 192.168.0.0 and 192.168.15.0

So unless there is a gateway between those two subnets they won't
communicate.

You could try setting a manual ip on the laptop in 192.168.0.(1-254)
Somewhere between 1 and 254 but try to pick a number known not to be
in use.

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9 14th August 04:54
gerald vogt
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Default Why can I ping in one direction but not the other


Well, as a complete peer-to-peer is not working now either, I thought
the solution should be inexpensive and thus a solution without new
hardware was preferable. Fixing the problem with minimal effort.

It kind of depends on the budget and the requirements of what you want
to have...

Gerald
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10 14th August 06:18
ron lowe
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Posts: 1
Default Why can I ping in one direction but not the other


His peer-to-peer network would continue to not work
across the static router for the reasons I outlined.
( no name resolution, no browsing. )

A possible no-new-hardware solution would be to use the linksys as
neither a NAT device OR a static IP router, but simply as a switch.

We couldUplink from one of the linksys LAN ports to the Netgear,
leaving the linksys WAN port unused. Also, we'd ensure DHCP
server is off on the linksys, allowing all DHCP to come from the netgear.

I chose not to reccommend this, because I didn't want to mess with the
exsisting VoIP configuration on the linksys, which is working.
I thought it best to leave that as-is.

--
Ron
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